The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A hybrid vehicle refers to a vehicle utilizing two or more types of power sources in order to drive a vehicle. Such a hybrid vehicle is typically a vehicle that utilizes an engine that draws a driving torque by combusting fuel as well as a drive-motor driven by a power of a rechargeable battery.
When the hybrid electric vehicle accelerates, a motor/generator assists in power for the acceleration, and the engine may be efficiently operated by an automatic shift control, thereby enhancing fuel consumption compared with a vehicle having a traditional combustion engine and an automatic transmission.
Such a hybrid electric vehicle is applied with a transmission that installed with a motor/generator.
The transmission of a hybrid electric vehicle typically includes a transmission case which is assembled in the order of a front cover, a gear case, a motor case, and a rear cover. A gear train is installed inside the gear case and the front cover, and a motor/generator is installed inside the motor case and the rear cover.
The gear train and the motor/generator generate heat and thus a cooling and lubricating system is desired for cooling and lubricating the gear train and the motor/generator.
According to a conventional lubrication system to cool and lubricate such heat sources, a hydraulic pump and a valve body are typically employed such that oil is forcedly circulated. Such a conventional system may become easily heavy-weighted due to the employed parts, and complex due to forced oil circulation routes.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.